RDA license: cost, courses & renewal
RDA is a state license, not a national one. In California: 7 pathways in, 6 required courses, a $120 application, and renewal every 2 years.
What's an RDA?
RDA (Registered Dental Assistant) is a state license that authorizes a dental assistant to perform expanded duties: coronal polishing, pit and fissure sealants, taking impressions, and other tasks your state writes into the scope. California's is the one most people mean. There's no national RDA. The letters mean whatever your state's dental board says they mean, and in several states they mean nothing at all, because those states don't license dental assistants.
RDA vs CDA vs everything else
A state license and a national certification both get called dental assistant credentials. Only the certification travels.
| RDA | A license from a state dental board. California's is the best known. It gives you legal scope, and it stops at the state line. |
|---|---|
| CDA | A national certification from the Dental Assisting National Board, made of 3 exams: General Chairside, Radiation Health and Safety, and Infection Control. It renews every year and needs current CPR. Some state boards accept it toward their own requirements. On its own it isn't a license. |
| RDAEF | California's next tier, Registered Dental Assistant in Extended Functions. More scope again, and a separate application. |
| Everything else | Other states use EFDA, EDDA, or their own labels for similar scope, with their own rules. Some require nothing. |
California treats an active DANB CDA as one of the 7 ways to qualify for its RDA exam, so the two stack rather than compete.
Who requires RDA
General and specialty dental practices ask for it where the state defines the credential. If the job includes coronal polishing, sealants, or taking impressions, the practice needs someone licensed to do it. Basic chairside assisting, sterilization, and front-office work usually don't require it, which is how most people start. Orthodontic practices in California have a separate Orthodontic Assistant permit for their own scope. Dental hygienists work under a different license entirely.
Requirements and eligibility
California lists 7 ways to qualify for the RDA exam.
- Finish a board-approved RDA educational program.
- Or work as a dental assistant for at least 15 months and 1,280 hours. Both numbers, not either.
- Or combine non-board-approved dental assisting education with work experience totaling the same 15 months and 1,280 hours.
- Or hold an active DANB CDA, having passed General Chairside, Radiation Health and Safety, and Infection Control.
- Or finish an alternative program: at least 500 hours of didactic and laboratory coursework plus 300 hours of clinical chairside experience.
- Or do a preceptorship: at least 500 hours of clinical chairside experience plus 300 hours of coursework.
- Or hold an active California RDH license issued on or after 1 January 2006.
Whichever route you take, you also pass the Registered Dental Assistant Combined Written and Law and Ethics Examination, run by PSI. There's no practical exam.
Cost, courses, and renewal
California requires 6 board-approved courses on top of your pathway, each with its own hour count and its own recency limit. They're separate from the exam, and each limit is measured back from your application date.
| Application fee | $120 |
|---|---|
| Exam | RDA Combined Written and Law and Ethics Examination, administered by PSI |
| Radiation Safety course | 32 hours or more, taken within the last 10 years |
| Coronal Polishing course | 12 hours or more, within the last 5 years |
| Pit and Fissure Sealants course | 16 hours or more, within the last 5 years |
| Infection Control course | 8 hours, within the last 2 years |
| California Dental Practice Act course | 2 hours, within the last 2 years |
| Basic Life Support | A current card. See BLS / CPR certification for what counts |
| Validity period | 2 years. It expires on the last day of your birth month in the second year |
| Renewal fee | $100, plus a $50 delinquency fee if you're more than 30 days late |
| Renewal requirement | 25 CE units, though not for your first renewal |
| Issuing body | Dental Board of California |
Figures are the Dental Board of California's, current as of July 2026. Two renewal quirks are worth putting in your calendar: your first renewal needs no CE at all, and if you were licensed on or after 1 January 2010 you've to complete a pit and fissure sealant course before your second renewal, on top of the 25 units.
What RDA means outside California
Check your own board before you spend anything, because the letters aren't portable. Some states license or register dental assistants and grant expanded functions through a state exam. Some accept DANB's certification toward their own requirements. Some use a different name for the same scope, usually EFDA or EDDA. And some have no dental assistant credential at all, in which case a dentist can delegate what state law allows and your training is a matter between you and your employer.
Moving states is where this costs you. A California RDA carries no automatic standing anywhere else, and the receiving board decides what your hours and coursework are worth. The CDA is the part that travels, which is why assistants who expect to move often hold it alongside the state license.
How to get certified
- Read your state dental board's rules first. If you're not in California, most of the numbers on this page don't apply to you.
- Pick your pathway. If you already hold a DANB CDA, or a California RDH issued since 2006, you may be closer than you think.
- Book the 6 required courses, watching the recency limits: radiation safety counts for 10 years, polishing and sealants for 5, infection control and the Dental Practice Act for 2, and your BLS card has to be current on the day you apply.
- Apply to the Dental Board of California and pay the $120.
- Pass the Combined Written and Law and Ethics Examination through PSI.
- Note your birth month. That's when the 2-year cycle ends.
CDA: the national certification
The CDA (Certified Dental Assistant) comes from the Dental Assisting National Board, not a state. It's built from 3 exams: General Chairside, Radiation Health and Safety, and Infection Control. Pass all 3 and you hold a credential that carries the same meaning in every state. The RDA license stops at the state line; the CDA doesn't. Renewal is annual and needs current CPR plus continuing dental education credits. On its own the CDA isn't a license to perform expanded functions. States decide whether to accept it toward their own requirements, and California counts an active CDA as one of its 7 RDA pathways.
EFDA: expanded functions by state
EFDA (Expanded Functions Dental Assistant, sometimes Expanded Function Dental Auxiliary) is the label many states outside California use for the same expanded scope an RDA covers: placing and finishing restorations, coronal polishing, and similar chairside work a dentist delegates. It's a state permit, so the rules are set locally. A common path is a dental assisting program plus EFDA coursework, then a written and clinical exam. Washington renews the license every year on your birthday; Wisconsin requires at least 70 hours of classroom instruction before you qualify. Several states accept a DANB CDA toward eligibility. Check the board where you plan to work, because the hours and exams don't carry over.
Dental radiology (x-ray) certification
Many states require a separate permit before a dental assistant can operate x-ray equipment, and it's one of the credentials people search for on its own. The usual gate is DANB's Radiation Health and Safety (RHS) exam, which state boards accept toward the permit. What sits on top of it varies: Texas issues an RDA x-ray certification, Maryland certifies a Dental Radiation Technologist after a 24-hour board-approved course plus the RHS or CDA exam, and Indiana grants a limited radiographic license once you pass the RHS exam. California folds radiation safety into the RDA license as a 32-hour course rather than a standalone permit. Confirm your state's rule before you assume x-ray duty is covered by whatever you already hold.
On the job
Employers verify your license number against the state board. Keep your address current with the board as well as with HR: that's where the renewal notice goes. Ask who pays for CE, because 25 units every 2 years is a real cost, and practices that want you polishing and placing sealants have a reason to cover it.
